Background Field
Embodiments of the subject matter described herein are related generally to generating and using a database for location or geographic based services and, and more particularly securing such databases during generation and use.
Relevant Background
Various location/geographic databases are currently available and/or are in the process of development to provide location-based services. Examples of such databases include, but are not limited to, databases for geographic maps, cell ID, access points (APs) and indoor building maps. Database vendors spend significant efforts and resources to generate and update these databases using various means such as crowdsourcing and war driving efforts.
In order to effectively use such databases to provide meaningful services to mobile devices, a small geographic subset of data from a database is typically downloaded to the mobile device. As mobile devices transition in-and-out of connectivity service, the downloaded geographic subsets of data enable a seamless location service experience for the mobile device user. Thus, the location based servers provide a way for the geographic subsets of data, generally referred to as tiles, to be downloaded from the servers.
The ability to download subsets of data from location based servers, however, places the database at risk of illegal data harvesting. For example, an illegal client, with knowledge of the Client-Server protocol, can access and download all of the tiles from the location based server. Additionally, as the content of the database is often developed using crowdsourcing techniques, another risk is an illegal client uploading malicious content into the database. It should be noted that in this context, the definition of illegal client is rather broad. For example, an authorized mobile device maybe considered an illegal client if using a WLAN access point simulator to illegally download database tiles from a location based server and copy the tiles from local storage. As an example, if a WiFi positioning server allows a client to download the regional access point database by sending a list of nearby access point Media Access Control (MAC) addresses, any illegal client can access and copy this database by constructing one MAC Address. By looping over all the possible MAC Addresses, a client can therefore download an entire access point database from the server.
Several precautions may be taken to prevent an attacker from easily harvesting a database. Nevertheless, most precautions result in simply slowing the process of illegally harvesting a database. One precaution requires client registration to prevent illegal harvesting of a database. However, client registration raises the issue of privacy, i.e., a database vendor is able to track a device based on its identification, making registration a less preferred choice for device authentication.